Measurements are provided in a patient of the functioning of various organs in a patient's body. For example, measurements are made of the functioning of the patient's heart and the patient's brain. These measurements are generally made by applying an electrode or electrodes to the skin of the patient at the appropriate position or positions on the patient's body.
The measurements of the functioning of different organs in the patient's body involve the acquisition of signals in different frequency ranges. For example, measurements of the patient's heart occur in a range of DC to approximately two hundred and fifty hertz (250 Hz) and measurements of the patient's brain occur in a range of DC to approximately one hundred and fifty hertz (150 Hz).
The measurement of the functioning of different organs in the patient's body involves signals of miniscule amplitude. For example, the range of voltages produced at an electrode attached to the patient's skin for a measurement of the patient's heart is approximately one half of a millivolt (0.5 mV) to approximately four millivolts (4 mV). The range of the voltages produced at an electrode attached to the patient's skin for a measurement of the patient's brain is approximately five microvolts (5 μV) to approximately three hundred microvolts (300 μV).
When an electrode is attached to the patient's skin to measure the function of an organ such as the patient's heart or brain, the signal generated from the organ has to penetrate from the patient's organ through the body and the patient's skin to the electrode.
Monitors have been provided for many years to measure the characteristics of a patient's heart. The monitors in the other class are disposed on belts which are wrapped around the patient's waist and attached at their opposite ends by a buckle or clasp so as to be retained on the patient's body at the patient's waist. A cable connects electrodes on the patient's body to the monitor. This is called an “ambulatory monitor”
The patient then engages in the normal activities for a period of approximately twenty four (24) hours. After the recording session, the patient returns the monitor to the doctor's office. The signals required for the monitor are then analyzed, either by the doctor or by someone knowledgeable with respect to heart signals, to determine if the patient's heart presents any problems.
There are at least two (2) major problems with the ambulatory heart monitors now in use. One problem is that the ambulatory heart monitor does not faithfully record the patient's heartbeat signals. This results in part from ambulatory movements of the patient during the twenty four (24) hour recording period. When the patient moves during the recording period, artifacts and noise signals are produced which cloud the heartbeat signals. Furthermore, the heartbeat signal is not faithfully reproduced when it is amplified.
Another problem is that the signals cannot be analyzed until the ambulatory monitor is returned to the doctor at the end of the twenty four (24) hour recording period. This is undesirable. It would be better if the heartbeat signals produced by the patient during the recording period could be instantaneously analyzed by experts to identify the problems, if any, in the patient's heart while the problems are occurring. This would be especially critical if the patient was suffering a heart attack during the testing period. Furthermore, it would be better if the signals could be instantaneously analyzed to determine the existence of the patient's heart problems and to determine the severity, if any, of the patient's heart problems and the steps, if any, that should or could be immediately taken, based upon the analysis, to ameliorate the patient's heart problems.